Lent can be a time of penitence, a time of repenting. These words, penitence and repenting, carry many connotations. In the Old Testament, the dominant image is turning toward God. In the New Testament, there are sometimes references to turning, but there is also the idea of changing your mind. Calvin emphasized "mortification" and "vivification"--dying to sin and becoming alive to the Holy Spirit.
I think that sometimes people confuse real, effective change in their lives with ideas of self-punishment. There is some theological truth to the fact that we're all sinful and have all fallen short. There is some theological truth to the fact that we are therefor deserving of punishment. These truths lead us to great appreciation of God's mercy and grace when we realize that our sins are forgiven. But sometimes this kind of thinking leads us to devise our own punishment for our own self-perceived guilt. In the lightest forms, these kinds of thoughts lead to "I'm giving up chocolate for Lent" or "I'm putting a pebble in my shoe so that I suffer a little with each step." I do not think these kinds of thoughts are healthy, and in the extreme can lead to dangerous self-destructive behaviors. Some will say that Jesus suffered on the cross, but I say that Jesus suffered on the cross for our sins so that we wouldn't have to. Penitence and repentance are not about suffering and punishment.
Penitence and repentance are about change. If I have bad habits, if I eat too much chocolate for instance, then giving up those bad habits is a good thing, not because of the suffering, but because of the improved living. The kind of change that penitence and repentance lead to requires, as a precursor, a great deal of self-reflection. The first step of turning toward God is realizing that we're not facing God to begin with. Reviewing our lives and identifying those places where we are sinful and falling short has to happen before we can change, but it doesn't have to be full of guilt. Realizing our bad habits of action or bad habits of thought can be a moment of joy because we are then empowered to change.
During Lent, you may have some spiritual disciplines that you find helpful. I am not asking you to change your spiritual disciplines, but I invite you to be very intentional about using them for the purpose of self reflection. I also urge you to avoid wallowing in guilt or self-punishment. Remember what I say every Sunday from the baptismal font: "Friends, believe the good news of the gospel. In Jesus Christ, we are forgiven." Instead, take all that energy and focus it on change for the better. Add self-reflection to your spiritual discipline, use that self reflection to motivate yourself to real changes, and focus on becoming alive to the Holy Spirit.